... function.3.4Retractable caterpillar chassis facilitates improving drilling work’s stability and reducing transport width. 3.5 Self- ... process. 3.10 Unique assistant windlass mechanism improves system’s working efficiency,guarantees accuracy of drilling depth measuring, ... motor,hydraulic valve). 3,Chassis parts—from ITALY BERCO S.P.A.(including caterpillar assembly,driving roller, guiding roller,track ...